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学者姓名：李炎锋
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Abstract ：
Human breathing is crucial for studying indoor environments and human health. Computational Fluid Dynamics (CFD) is a key tool for simulating human respiration. To enhance the accuracy of CFD simulations and reduce computation time, a new simulation strategy for human respiration is proposed in this paper. The effects of steady versus unsteady boundary conditions on simulation results were examined. For the unsteady boundary, sinusoidal exhalation velocities and non-inhalation gas were assumed, while the steady boundary involved constant velocities during both exhalation and inhalation phases. The jet center trajectory under different boundary conditions was analyzed and compared with experimental data. Additionally, variations in pollutant dispersion near the mouth under the two boundary conditions were discussed. Furthermore, the paper compared the calculation accuracy, calculation time and memory occupied by a single turbulence model or switching flow character models in human respiration simulation. Differences in exhaled gas vorticity and jet penetration depth across different flow models were identified. Finally, combined with the non-iterative algorithm, the optimal strategy of human respiration simulation was proposed. Results show that under the comprehensive consideration of calculation accuracy, calculation time and memory occupancy, using sinusoidal expiratory boundary conditions combined with the PISO algorithm, with the RNG k-epsilon model during expiratory phase, and switching into the laminar flow during inspiratory phase, is the optimal strategy of simulating human breathing.
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| GB/T 7714 | Gao, Feng , Li, Yanfeng , Su, Zhihe et al. Optimal human respiratory simulation for exhaled gas based on CFD method [J]. | PLOS ONE , 2024 , 19 (11) . |
| MLA | Gao, Feng et al. "Optimal human respiratory simulation for exhaled gas based on CFD method" . | PLOS ONE 19 . 11 (2024) . |
| APA | Gao, Feng , Li, Yanfeng , Su, Zhihe , Wang, Chunlin , Wang, Haidong , Li, Junmei . Optimal human respiratory simulation for exhaled gas based on CFD method . | PLOS ONE , 2024 , 19 (11) . |
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Abstract ：
For an underground hydropower stations, understanding the heat and mass transfer behaviour of outdoor air flowing through ventilation tunnel can help improve the design of ventilation systems and reduce energy consumption. The aim of this paper is to investigate the influences of summer outdoor meteorological parameters on the tandem ventilation process and the designed parameter requirements in the main plant. A series of field tests and numerical simulations were conducted to determine the variations in outdoor air parameters passing through the ventilation tunnel. Theoretical analyses were developed to clarify the variations in air parameters through the ventilation process in i-d diagram. Results show that the outdoor meteorological temperature has the largest influence on heat transfer between the ventilation tunnel and airflow. The relative humidity in the air at the tunnel outlet could reach 90% under most conditions. The reasonable air supply area and the critical air supply temperature of the mechanical ventilation were determined. Once the outdoor air passes through the ventilation tunnel and the i-d diagram falls in air supply area II, the outlet air can be directly supplied to the main plant. For conditions that did not satisfy the mechanical air supply scheme, the measure of setting dehumidifiers at 200-250 m arranging intervals in the tunnel were proposed to improve the air humidity. Based on the meteorological parameters of typical climate zones in China, a reasonable air supply scheme for the main plant was determined. The results could technically guide the ventilation design of underground hydropower stations, which can help to enchance energy-efficient and low-carbon ventilation schemes.
Keyword ：
outdoor meteorology outdoor meteorology i-d diagram i-d diagram underground tunnel underground tunnel heat transfer heat transfer Ventilation scheme Ventilation scheme
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| GB/T 7714 | Xu, Desheng , Li, Yanfeng , Tian, Wei et al. A study of the correlation between summer outdoor meteorological parameters and hydropower station ventilation schemes [J]. | INTERNATIONAL JOURNAL OF VENTILATION , 2024 . |
| MLA | Xu, Desheng et al. "A study of the correlation between summer outdoor meteorological parameters and hydropower station ventilation schemes" . | INTERNATIONAL JOURNAL OF VENTILATION (2024) . |
| APA | Xu, Desheng , Li, Yanfeng , Tian, Wei , Chen, Chao , Yang, Xin , Zhong, Hua . A study of the correlation between summer outdoor meteorological parameters and hydropower station ventilation schemes . | INTERNATIONAL JOURNAL OF VENTILATION , 2024 . |
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Abstract ：
In this research, the influence of confined space size on the temperature distribution characteristics of internal window plumes from well-ventilated compartment fires was studied. Theoretical analysis was firstly used to establish a mathematical model for the smoke after ejecting from the window in the space. The study considered fire heat release rate and vertical height as dependent variables. Numerical simulations and experimental methods were carried out to study the temperature variations. A critical distance L2 was obtained. Results show that when the space D between the vertical retaining wall and the building fa & ccedil;ade is greater than L2, the variation of D has little influence on radial temperature. Once D is less than L2, the radial temperature distribution inside the confined space will tend to be consistent, and the temperature in the confined space sharply increases as D decreases. In addition, a dimensionless model was derived to quantify the relationship between temperature rise and vertical height. The experimental and numerical simulation results were processed, which are in good agreement with the model. The study can provide a framework for managing building safety.
Keyword ：
confined space confined space temperature distribution temperature distribution window plume window plume well-ventilated compartment fires well-ventilated compartment fires
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| GB/T 7714 | Dong, Qiwei , Li, Yanfeng , Li, Junmei et al. The Influence of Confined Space Size on the Temperature Distribution Characteristics of Internal Window Plume from Well-Ventilated Compartment Fires [J]. | FIRE-SWITZERLAND , 2024 , 7 (5) . |
| MLA | Dong, Qiwei et al. "The Influence of Confined Space Size on the Temperature Distribution Characteristics of Internal Window Plume from Well-Ventilated Compartment Fires" . | FIRE-SWITZERLAND 7 . 5 (2024) . |
| APA | Dong, Qiwei , Li, Yanfeng , Li, Junmei , Xie, Fei , Xu, Desheng , Su, Zhihe . The Influence of Confined Space Size on the Temperature Distribution Characteristics of Internal Window Plume from Well-Ventilated Compartment Fires . | FIRE-SWITZERLAND , 2024 , 7 (5) . |
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Abstract ：
This study proposes a model for the quantitative evaluation of the life-cycle carbon footprints of large sporting events and the uncertainties related to them. The model was used to analyze the case of a mega sporting event in Beijing, China. First, the quantitative model for the evaluation of the carbon footprints of mega sporting events includes a preparation stage, a holding stage, and an end stage. These stages consider the energy and resources used for construction, operation, transportation, catering, and accommodation. Second, this study proposes a prediction model using model-based and simulation-based methods to address the difficulty of obtaining traffic activity. Third, a semi-quantitative method that combines a data quality indicator and stochastic simulation is adopted for the uncertainty analysis of mega sporting events. Finally, a case study is used to indicate that the preparation stage of a mega sporting event accounts for the highest CO2 emissions at 92.1%, followed by 7.5% in the holding stage and 0.4% in the end stage. The total life-cycle CO2 emissions of a sustainable scenario of a mega sporting event in Beijing amount to 205,080.3 t CO2e, and the per capita CO2 emissions during the event's holding stage amount to 0.26 t CO2e/person. The uncertainty in the input parameters is 0.0617, indicating that the uncertainty of the model is low, and the reliability of the results is high.
Keyword ：
life cycle life cycle mega sporting events mega sporting events carbon footprint carbon footprint environmental impact environmental impact uncertainty analysis uncertainty analysis
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| GB/T 7714 | Wang, Hongyan , Tian, Jibang , Li, Yanfeng et al. Study on Life-Cycle Carbon Footprints and an Uncertainty Analysis of Mega Sporting Events: An Analysis in China [J]. | BUILDINGS , 2024 , 14 (8) . |
| MLA | Wang, Hongyan et al. "Study on Life-Cycle Carbon Footprints and an Uncertainty Analysis of Mega Sporting Events: An Analysis in China" . | BUILDINGS 14 . 8 (2024) . |
| APA | Wang, Hongyan , Tian, Jibang , Li, Yanfeng , Wang, Yang , Lu, Yao , Zhang, Jianye et al. Study on Life-Cycle Carbon Footprints and an Uncertainty Analysis of Mega Sporting Events: An Analysis in China . | BUILDINGS , 2024 , 14 (8) . |
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Abstract ：
This study explores the impact of climate variability on the operation of sustainable ventilation systems in urban infrastructure, with a focus on smoke movement in metro stations under varied external climatic conditions. Smoke characteristics and ventilation strategies in an atrium-type metro station are investigated using numerical simulations. The simulations reveal the influence of external climate on smoke movement through the atrium and roof windows, with particular attention to outdoor temperature and wind velocity. The study designs different ventilation strategies for smoke control that incorporate meteorological data, evaluating smoke visibility, CO distribution, and smoke extraction efficiency. The findings indicate that under severe external climates of low temperatures and high wind velocities, smoke extraction from roof window outlets is challenging. The adverse effects of external climate decrease the natural smoke extraction efficiency, increase the CO concentration, and reduce the safe visibility area. However, improved ventilation measures, such as the platform make-up air system and roof mechanical extraction system, can significantly enhance smoke control performance and facilitate safe evacuation. The study also employs the NSGA-II multi-objective optimisation method to obtain optimal ventilation strategies for different climates, balancing three optimisation objectives of operating energy consumption, safe visibility area, and smoke extraction efficiency. The outcomes show that the recommended values of V-p are 20%-30 % (0 degrees C <= T-o <= 40 degrees C) and 40 % (-40 degrees C <= T-o<0 degrees C), v(r) are 0.3 (10 degrees C <= T-o <= 40 degrees C) and 0.4 (-40 degrees C <= T-o < -10 degrees C), and V-c are all lower than 4 %. As wind velocity increases, the recommended values need to be enhanced. This research contributes to sustainable urban development by offering a framework for managing public safety and energy efficiency in the context of climate variability.
Keyword ：
Ventilation system Ventilation system Climate change Climate change Energy consumption Energy consumption Fire safety Fire safety Multi-objective optimisation Multi-objective optimisation
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| GB/T 7714 | Xu, Desheng , Li, Yanfeng , Li, Jiaxin et al. Climate-adaptive fire smoke ventilation strategies for atrium-type metro stations: A NSGA-II multi-objective optimisation study [J]. | ENERGY , 2024 , 306 . |
| MLA | Xu, Desheng et al. "Climate-adaptive fire smoke ventilation strategies for atrium-type metro stations: A NSGA-II multi-objective optimisation study" . | ENERGY 306 (2024) . |
| APA | Xu, Desheng , Li, Yanfeng , Li, Jiaxin , Zhong, Hua , Li, Junmei , Huang, Youbo . Climate-adaptive fire smoke ventilation strategies for atrium-type metro stations: A NSGA-II multi-objective optimisation study . | ENERGY , 2024 , 306 . |
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Abstract ：
Asymmetrical V-shaped tunnels often appear in tunnels crossing the river or urban underground road tunnels. The smoke flow inside is affected by a lot of factors. A full understanding of the smoke flow in this kind of tunnel is the basis of the smoke control. In this study, the effects of slope composition and fire heat release rate (HRR) on the longitudinal induced airflow velocity, the smoke back-layering length at the small slope side, and the maximum ceiling temperature were studied by the numerical method. The results show that when the fire occurs at the slope change point of the V-shaped tunnel, the maximum ceiling temperature decreases with the increase in the slope of the large-slope side tunnel. The longitudinally induced velocity is primarily related to the slope of the large-slope side tunnel and the fire HRR. When the slope difference between the side tunnels or the slope of the large-slope side tunnel is large, the smoke in the small-slope side tunnel flows back toward the fire source after reaching its maximum dispersion distance and then reaches a quasi-steady state. The smoke back-layering length is mainly affected by the slope and length of the large-slope side tunnel. When the slope of the large-slope side tunnel is 9%, the induced airflow velocity from the small-slope side can prevent the spread of smoke. The empirical models of the smoke back-layering length and the longitudinal induced airflow velocity in the small-slope side tunnel are drawn, respectively, by the theoretical analysis and the numerical results. This study can provide technical support for the design and operation of smoke control systems in V-shaped tunnels.
Keyword ：
back-layering length back-layering length maximum ceiling temperature maximum ceiling temperature induced airflow velocity induced airflow velocity smoke spread smoke spread asymmetric V-shaped tunnel asymmetric V-shaped tunnel
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| GB/T 7714 | Tu, Dengkai , Li, Junmei , Li, Yanfeng et al. Numerical Study on the Influence of the Slope Composition of the Asymmetric V-Shaped Tunnel on Smoke Spread in Tunnel Fire [J]. | FIRE-SWITZERLAND , 2024 , 7 (10) . |
| MLA | Tu, Dengkai et al. "Numerical Study on the Influence of the Slope Composition of the Asymmetric V-Shaped Tunnel on Smoke Spread in Tunnel Fire" . | FIRE-SWITZERLAND 7 . 10 (2024) . |
| APA | Tu, Dengkai , Li, Junmei , Li, Yanfeng , Xu, Desheng . Numerical Study on the Influence of the Slope Composition of the Asymmetric V-Shaped Tunnel on Smoke Spread in Tunnel Fire . | FIRE-SWITZERLAND , 2024 , 7 (10) . |
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Abstract ：
人字坡隧道较多地出现在山岭隧道和新建的城市交通隧道中,火灾时其内部烟气流动复杂,纵向通风时,对烟气实施有效控制困难.通过搭建1:20的人字坡隧道模型试验台,对火源位于变坡点时,非对称人字坡隧道内不同的坡度组成和不同火源功率作用下的临界风速进行了研究.研究结果表明:在小坡度侧实施纵向通风时,临界风速大于同一断面和火源功率作用下平直隧道内的临界风速,且临界风速随变坡点两侧坡度差的增加而增大;在大坡度侧施加纵向通风时,临界风速小于平直隧道内的临界风速,且临界风速随着坡度差的增大而减小.为了便于工程应用,综合模型试验结果,对平直隧道的临界风速模型进行了坡度修正,得到了可用于人字坡隧道的临界风速修正系数.
Keyword ：
纵向通风 纵向通风 人字坡隧道 人字坡隧道 模型试验 模型试验 临界风速 临界风速
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| GB/T 7714 | 郭志成 , 李俊梅 , 欧阳力 et al. 非对称人字坡隧道火灾纵向通风临界风速的试验研究 [J]. | 消防科学与技术 , 2024 , 43 (9) : 1253-1258 . |
| MLA | 郭志成 et al. "非对称人字坡隧道火灾纵向通风临界风速的试验研究" . | 消防科学与技术 43 . 9 (2024) : 1253-1258 . |
| APA | 郭志成 , 李俊梅 , 欧阳力 , 李炎锋 . 非对称人字坡隧道火灾纵向通风临界风速的试验研究 . | 消防科学与技术 , 2024 , 43 (9) , 1253-1258 . |
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Abstract ：
With the development of the world economy and the depletion of natural resources, the energy crisis and the deterioration of the ecological environment have become key issues for sustainable development worldwide. To achieve the goal of "carbon neutrality," the issue of carbon emissions will naturally become a focus. Large-scale events are generally accompanied by a sharp increase in carbon emissions. In this paper, the passenger flow simulation and carbon emissions calculation during the 2022 Beijing Yanqing Winter Olympics and Winter Paralympic Games are carried out. The VISSIM is used to simulate the passenger flow during its operation to obtain relevant parameters, and the emissions factor method is used to calculate carbon emissions. The establishment of a reasonable and accurate simulation model of large-scale activity carbon emissions plays an important role in promoting the sustainable development of urban transportation.
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| GB/T 7714 | Wang, Yang , Zhang, Jian-Ye , Zhang, Yu-Meng et al. Carbon Emissions Estimation for Passenger Transportation in Yanqing Competition Venue of the 2022 Olympic Winter Olympics and Paralympics [J]. | CICTP 2023: INNOVATION-EMPOWERED TECHNOLOGY FOR SUSTAINABLE, INTELLIGENT, DECARBONIZED, AND CONNECTED TRANSPORTATION , 2023 : 70-78 . |
| MLA | Wang, Yang et al. "Carbon Emissions Estimation for Passenger Transportation in Yanqing Competition Venue of the 2022 Olympic Winter Olympics and Paralympics" . | CICTP 2023: INNOVATION-EMPOWERED TECHNOLOGY FOR SUSTAINABLE, INTELLIGENT, DECARBONIZED, AND CONNECTED TRANSPORTATION (2023) : 70-78 . |
| APA | Wang, Yang , Zhang, Jian-Ye , Zhang, Yu-Meng , Li, Yan-Feng , Wang, Hong-Yan . Carbon Emissions Estimation for Passenger Transportation in Yanqing Competition Venue of the 2022 Olympic Winter Olympics and Paralympics . | CICTP 2023: INNOVATION-EMPOWERED TECHNOLOGY FOR SUSTAINABLE, INTELLIGENT, DECARBONIZED, AND CONNECTED TRANSPORTATION , 2023 , 70-78 . |
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Abstract ：
The critical velocity, confinement velocity and smoke back-layering length are significant factors for smoke control in a tunnel fire. This research aims to analysis the correlation of these 3 key smoke control parameters in the different door opening scenarios during a fire in the metro train carriage that stopped in the tunnel. Scaled model experiment measurement and numerical simulations were carried out for the propagation and control of smoke. Five fire locations in the train and two side doors opening scenarios of the train were considered. Results show that smoke back-layering length in the train can be barely influenced by the activation time of the lon-gitudinal ventilation system. However, the opening of side doors could result in a shorter smoke back-layering length in the train. Furthermore, we present a dimensionless correlation for the critical velocity and confine-ment velocity of underground train fires caused by fires in the double-length narrow space of an underground tunnel. This study provides a predictive model for the design of smoke control systems for fire of train stopped in underground tunnels.
Keyword ：
Confinement velocity Confinement velocity Door opening scenarios Door opening scenarios Underground tunnel Underground tunnel Fire Fire Critical velocity Critical velocity
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| GB/T 7714 | Su, Zhihe , Li, Yanfeng , Feng, Shan et al. A study of the critical velocity and the confinement velocity of fire accident in a longitudinally ventilated underground train with different door opening scenarios [J]. | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2023 , 131 . |
| MLA | Su, Zhihe et al. "A study of the critical velocity and the confinement velocity of fire accident in a longitudinally ventilated underground train with different door opening scenarios" . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 131 (2023) . |
| APA | Su, Zhihe , Li, Yanfeng , Feng, Shan , Zhong, Hua , Li, Junmei , Liu, Wenbo et al. A study of the critical velocity and the confinement velocity of fire accident in a longitudinally ventilated underground train with different door opening scenarios . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2023 , 131 . |
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Abstract ：
This research aims to establish a series of small-scale experiments to analyze the effect of ramp slopes on the temperature distribution of Liquefied Petroleum Gas (LPG) fire in a model branched tunnel under longitudinal ventilation. The heat release rate under experimental conditions reached 2.57 kW to 7.70 kW and five ramp slopes of 0 %, 3 %, 5 %, 7 % and 9 % were conducted. For a specific given bifurcation angle, the maximum exceedance temperature of the fire in the expanding region before the bifurcation angle is measured and ana- lysed. Results show that the maximum exceedance temperature in the main tunnel increases as the ramp slope decreases, which is mainly because the stack effect enhances the entrainment of the air and accelerates the smoke flow. Furthermore, the modified model of the maximum exceedance temperature, which could consider the influence of ramp slope for a branch tunnel fire is established according to the experimental results. The pre- dicted results agree well with those of the experimental study for the main tunnel. The results could provide a reference and contribute to the knowledge of smoke extraction strategies designed for branched tunnels.
Keyword ：
Ramp slopes Ramp slopes Longitudinal ventilation Longitudinal ventilation Maximum exceedance temperature Maximum exceedance temperature Branched tunnels Branched tunnels
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| GB/T 7714 | Li, Jiaxin , Li, Yanfeng , Li, Junmei et al. Experimental analysis of the effect of the ramp slopes on the maximum exceedance temperature in a branched tunnel fire [J]. | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2023 , 131 . |
| MLA | Li, Jiaxin et al. "Experimental analysis of the effect of the ramp slopes on the maximum exceedance temperature in a branched tunnel fire" . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 131 (2023) . |
| APA | Li, Jiaxin , Li, Yanfeng , Li, Junmei , Zhong, Hua , Zhao, Jianlong , Xu, Desheng . Experimental analysis of the effect of the ramp slopes on the maximum exceedance temperature in a branched tunnel fire . | TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY , 2023 , 131 . |
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